Finely comminuted bone graft is important to successful total joint replacement especially for porous coated implants, spinal fusions and repair of defects caused by trauma. Therefore, it is necessary to have an apparatus which will comminute homogeneous or autogeneous bone into substantially homogeneous particles in a sterile environment.
One such known prior art apparatus includes a rotating cutter which is similar to a drill bit and a hopper into which bone fragments are placed. The operator grasps a handle which brings a compression plate into contact with the bone fragments. The compression plate pushes the bone fragments in the hopper into contact with the cutter. The bone fragments are milled into particles and collected in a tray below the cutter. The cutter may be powered by an electric motor or an air powered motor. This apparatus however, is not entirely safe to operate. The housing does not completely encase the cutter or motor making it possible to injure the operator. Additionally, the cutting blade may be operated even when the unit is partially disassembled. This is particularly dangerous since any such apparatus must be disassembled and reassembled after each use in order to clean and sterilize it.
Another prior art bone comminuting apparatus includes an air powered motor and a rotating cutting blade. This model includes a housing which completely encloses the motor and cutting blade. There is a generally horizontal chute into which bone pieces are placed prior to grinding. A push rod is used to move the bone pieces into the cutting chamber where they are comminuted. This unit does not provide an automatic shutoff to prevent operation of the cutter when the unit is disassembled for cleaning and sterilization.
There exists a need in the art for a bone comminuting device that produces substantially homogeneous bone particles, which may be readily disassembled and which includes additional safety features to protect the user.